1. Field of the Invention
The present invention relates to a connector having mating units for making an engagement of terminals accommodated therein and, more particularly, to a connector which forcibly sets the mating units at a pre-engagement position in which the terminals are not electrically connected when the terminals are incompletely engaged so as to prevent the terminals from temporarily connecting with each other.
2. Description of the Prior Art
In FIGS. 7, 8, and 9, a conventional connector is shown. The connector Cp includes a receptacle unit 2 with a male terminal 1 accommodated therein and a plug unit 4 with a female terminal 3 accommodated therein. The plug unit 4 is inserted into an insertion hole 2a formed on the front side of the receptacle unit 2 such that a forward end 1c of male terminal 1 moves toward an internal element 3c of female terminal 3, as shown in FIG. 7.
During this operation, a projection 4b formed in a trapezoid shape on the upper surface of a flexible arm 4a abuts an engaging part 2b formed in the open end of the insertion hole 2a. Further insertion of the plug unit 4 causes the engaging part 2b to press the flexible arm 4a downward, and the forward end 1c of the male terminal 1 contacts the internal element 3c, as shown in FIG. 8.
When the projection 4b completely passes through the engaging part 2b, the flexible arm 4a rises up so that the engaging part 2b fits in a locking cavity 2c formed backside of the engaging part 2b, and thus the receptacle and plug units 2 and 3 are locked at this lock position. At this lock position, the terminals 1 and 3 are connected to each other securely, as shown in FIG. 9.
When this kind of connector Cp in such conditions shown in FIGS. 7 or 8 is installed in the automobile, the plug unit 4 which is not locked by the engaging members 4b and 2c is likely to accidentally be removed from the receptacle unit 2 due to the vibrations mainly occurring while the automobile drives. Such a connector Cp in which the terminals 1 and 3 are completely separated and non-conductive, as shown in FIG. 7, can be easily detected by the quality inspection of the automobile, and it is possible to recover the disengagement.
However, such a connector Cp in which the terminals 1 and 3 are temporality connected, as shown in FIG. 8, can not be detected by the automobile's quality inspection, because the terminals 1 and 3 are conductive. Therefore, thus incompletely engaged connector which has passed the quality inspection may disengage so that the terminals 1 and 3 become non-conductive during the driving of the automobile, sometimes causing serious accidents. Finally, this temporarily engaged plug unit 4 completely removes from the receptacle unit 2.